Refrigeration



June 1940- P. P. ANDERSON, JR & 9

REFRI GERATIDN Filed Dec. 31. 1937 INVENTOW & ATTORNEY.

Patented June 4, 1940 UNITED STATES P'ATENTOFFICE azoam REFRIGERATION Philip P. Anderson, Jr.,

to Servel, Inc., New York, N. Y., a corporation of Delaware Evansville, Ind., assignor Application December 31, 1937, Serial No. 182,'707

3 Claims.

My lnvention relates to an absorption type reirigeration system and` it is an object of the invention to provide a system of this type having greater efliciency.

The single figure of the drawing shows more or less diagrammatically an absorption refrigeration system making use of an auxiliary pressure equalizing fluid and embodying the invention.

A generator lo comprises an upright vessel through which extends a flue ll. The generator is divided by a partition |2 into an upper chamber u and lower chamber l4. The generator is heated by a gas burner I5 arranged so that the tlame is projected into the lower end of the fiue Il. Any other suitable heating means may be provided as, for instance, an electric heating element or a liquid fuel burner.

An absorber comprises a finned conduit IS and a vessel ll. The lower end of conduit IS is connected by conduit ID to the upper part of vessel l'l. An evaporator I! comprises a coil located in an insulated refrigerator storage compartment 20. The evaporator and absorber are interconnected by members including a gas heat exchanger 2l as hereinatter described. The generator and absorber are interconnected by members including a. triple heat exchanger 22. The generator is connected to an air cooled condenser 23 by members also including heat exchanger 22, and the condenser is connected to the evaporator IS.

The system contains a retrigerant fluid such as ammonia, a liquid absorbent for the refrigerant such as water, and an auxiiary pressure equalizing fluid such as hydrogen. The fluids may be introduced into the system through a charglng plug, not shown, in the absorber vessel ll. A water solution of ammonia having a. concentration of about 30% by weight, is inserted until the liquid level rises to the level of the charging plug. Hydrogen is then introduced at `a pressure such that the total pressure in the system will be the condensing pressure of ammonia at a fairly high room temperature.

In operation, refrigerant vapor is expelled from solution by heating in the generator o. Vapors are produced in both chambers l3 and !4. Vapors formed in chamber |4 depress the liquid 50 in this chamber` and rise through conduit 24 to a separating or circulation vessel 25, causing flow of liquid by vapor liquid lift action from chamber l4 through conduit 24 into vessel 25. Liquid is conducted from chamber !3 to chamber l4 through a conduit 24 which connects the lower part of chamber l3 to the lower part bf chamber l4.

Vapors formed in chamber |3 flow from the upper part of this chamber through a conduit 21 to one end of the outside passage 28 of the triple heat exchanger 22. Vapors from circulation vessel flow through a conduit 29 and conduit 21 into the outside heat exchanger passage 28. From the lower end of the heat exchanger passage 28, ammonia vapor flows through a conduit 30 to the upper end of the condenser 23. Ammonia vapor is condensed to liquid *in the condenser 23 and the liquid ammonia flows through a conduit 3l into the upper end of the evaporator 19.

Liquid ammonia flows downward in evaporator IS and evaporates and diffuses into hydrogen producing a refrigerating eifect. The mixture of hydrogen gas and ammonia vapor, referred to as strong or rich gas, flows from the upper end of evaporator !9 through a conduit 32, the inner passage 33 of gas heat exchanger ZI and conduit, !8 to the lower end of the absorber !6.

Weakenedabsorption liquid, referred to as weak solution, flows from the circulation 'vessel 25 through a conduit 34, the'inner p'assage 35 of the heat exchanger 22, and a conduit 36 to the upper end of absorber IG.- Weak solution flows downward in absorber !6 and absorbs ammonia vapor out of the gas. Weak or poor gas flows from the upper end of absorber IS through conduit 31, the outer passage 38 of gas heat exchanger 2l, and conduit 39 back to the lower end of evaporator IS.

Enriched absorption liquid, referred to as rich or strong solution, flows from the lower end of absorber IS into the absorber vessel l'l. Strong solution flows from vessel ll through a conduit 40, the middle passage 4| of the heat exchanger 22, and conduit 42 into the upper chamber !3 of the generator.

The lower end of condenser 23 is connected by a conduit 45, a vessel' 48, and a conduit 45a t conduit s in the gas circuit. This path of flow may be referred to as a vent, and vessel 48 pro- I vides a storage chamber for auxiliary fluid which is displaced into the gas circuit under high room temperature conditions in a known manner.

The, described circulation of gas through and 50 between the evaporator and absorber occurs automatically due to difference in weights of the columns of rich and weak gas as described in Patent 1,609,334 to von Platen and Munters. Flow of Weak solution from the generator III to the absorber !6 takes place by vapor liquid lift through conduit 24 and gravity flow from vessel 25 in the previously described path. Flow of strong solution takes place by gravity from the absorber vessel Il in the described path of flow to the generator o. The upper end of the middle heat exchanger passage 4| is connected to the lower part of a vessel 43 and the upper end of conduit 42 extends upward into the upper part of vessel 43. The upper part of vessel 43 is connectedby a conduit 44 to the vapor conduit 29 for equalizaton of pressure in vessel 43 and chamber l3 of the generator. The level of strong solution rises in absorber vessel I'I and vessel 43 until it reaches the upper end of conduit 42 whereupon liquid overflows into conduit 42 and flows as described into the generator.

The triple heat exchanger 22 is located below the surface levels of liquid in the absorber vessel I'I and vessel 43, and also below the surface level in circulation vessel 25 as determined by the point of overfiow from the upper end of conduit 36 into the upper end of absorber !6.

In the triple heat exchanger 22, heat is transferred from weak solution flowing through inner passage 35 to cooler rich solution flowing through middle passage 4l. Heat is also transferred from vapors fiowing in outside passage 28 to the cooler rich solution fiowing in middle passage 4I. Both the weak solution and vapors flow in countercurrent relation through the heat exchanger to the strong solution. Thus, heat from the generator I which has been added to the weak solution 'and vapors is transferred in the triple heat exchanger 22 to the strong solution and thereby returned to the generator.

cooling of vapors in the outside heat exchanger passage 28 is accompanied by condensation, the heat of condensation being transferred to the strong solution. This condensation effects removal of water vapor, this being referred to as rectification. The condensate formed in the outsidepassage 28 of the heat exchanger drains into a vessel 46 and thence through a conduit 41 and conduit 42 back to the generator o. The levels of liquid are substantially the same in vessel 46, conduit 42, and chamber l3 of the generator o. This liquid level provides the reaction head or liquid column for balancing the fluid column in the vapor lift conduit 24. The vessel 46 provides an enlarged chamber which acts to produce stabllity of level in chamber l3 of the generator.

various changes and modiflcations may be made within the scope of the invention which is not limited except as indicated in the following claims.

What is claimed is:

1. An absorption refrgeration system including a generator having a plurality of compartments one above the other and a heating flue extending upward through said compartments, an absorber, conduits for circulation of absorption liquid through and between said generator and absorber including a liquid heat exchanger and a vapor liquid lift conduit connected to the lowest of said generator compartments to cause said circulation of absorption liquid, a rectifier for vapor from said generator, arranged in direct heat transfer relation with said liquid heat exchanger, and a conduit for conducting liquid condensate by gravity from said rectifier to said generator.

2. An absorption refrgeration system including a plurality of places of heating, a place of absorption, a vapor liquid lift conduit for raising liquid from one of said places of heating, a conduit for conducting raised liquid to said place of absorption, a conduit for conducting enriched liquid from said place of absorption to another of said places of heating, a conduit for conducting liquid from said second place of heating to said first place of heating, a rectifier for vapor from said places of heating, arranged in direct heat transfer relation to said conduit for enriched absorption liquid, and a conduit for conducting liquid condensate by gravity from said rectifier to said second place of heating.

3. An absorption refrgeration system including a condenser, an evaporator, an absorber, a generator including a heated chamber, a rising conduit having its lower end extending into said heated chamber and forming a vapor lift by which vapor formed by heating of liquid in said chamber raises liquid toa level from which it fiows by gravity to said absorber, a rectifier for vapor flowing from said generator to said condenser and located at a level below the surface level of liquid in said absorber, and conduits interconnecting said absorber and generator and also connecting said rectifier to said generator so that liquid flows by gravlty from both said absorber and said rectifier to said generator.

PHILIP P. ANDERSON, JR. 

